The utility model relates to an assembly type section steel overhung protective shed. The assembly type section steel overhung protective shed comprises a base and a shed body, wherein the base is arranged in parallel with building floors; one end of the base is supported on a main body structural beam of any building floor, and the other end of the base extends out of any building floor; the base comprises more than two I-shaped steel main beams; a plurality of steel bar transverse beams are vertically connected between the two I-shaped steel main beams; steel plates are paved on the plurality of steel bar transverse beams; a plurality of support steel pipes are vertically welded on the I-shaped steel main beams at certain intervals; a main steel pipe is supported on the plurality of support steel pipes by welding; scaffold boards are paved on two main steel pipes supported on the two I-shaped steel main beams respectively; the shed body comprises a shed body framework and a protective net; the shed body framework comprises scaffolds supported at the near ends of the I-shaped steel main beams and the building floors, and framework steel pipes vertically welded at the far ends of the building floors; the protective net is stretched between the scaffolds and the framework steel pipes as well as between two adjacent framework steel pipes.